After a decade of increasing seismic activity, volcanic unrest in the glacier covered Bárdarbunga volcano suddenly escalated into a minor subglacial eruption on 16 August 2014. In the following weeks seismic activity soared and surface deformation of tens of cm were observed, caused by rifting and a dyke intrusion, which propagated over 40 km northward from the central volcano. A few short-lived minor subglacial eruptions occurred above the intrusion in the following two weeks. The dyke propagation ended when a fissure eruption started on 29 August, outside the glacial margin. This first eruption was short lived, but two days later a second, sustained eruption started from the same fissure, with extrusion rates of 200 m3/s. The effusive eruption produced primitive magma with high rates of SO2 emission and a low lying volcanic cloud, rising to a few km height. Within days, the magma extrusion rate grew to match the inflow rate into the fissure and crustal extension diminished. Three weeks into the unrest period over 20 shallow earthquakes with magnitudes over MW5 had occurred at the volcano, at shallow depth along the caldera rim. Subsequent surveying of the ice surface revealed around 20 m vertical subsidence of the caldera over this time and the possibility of a caldera collapse. The volcano is the focus of the European research project FutureVolc resulting in a large number of multidisciplinary observations of the event.

The Bárdarbunga volcano and its associated fissure swarm in Iceland’s Eastern Volcanic Zone is a highly active system with over 20 eruptions in the last 11 centuries. The location of this active volcano and much of the fissure swarm under several hundred metres thick ice gives rise to a multitude of major hazards, including explosive, phreatomagmatic subglacial eruptions in the caldera or on the fissure swarm with associated subglacial floods (jökulhlaups) and high-rising volcanic ash plumes, as well as fissure eruptions extruding large volumes of lava.

We invite observational and modelling contributions focused on this eruption from all fields of Earth science as well as hazard analyses.